*2.7. Water-Oxygen Barrier Properties of CS/PVOH/HNT and CS/PVOH/TO@HNT Films*

*2.7. Water-Oxygen Barrier Properties of CS/PVOH/HNT and CS/PVOH/TO@HNT Films* In Table 2 the water-oxygen transmission rate values for all CS/PVOH/HNT and CS/PVOH/TO@HNT films as well as pure CS/PVOH films are listed. By multiplying water-oxygen transmission rate values with film thickness the water diffusivity (D) and In Table 2 the water-oxygen transmission rate values for all CS/PVOH/HNT and CS/PVOH/TO@HNT films as well as pure CS/PVOH films are listed. By multiplying water-oxygen transmission rate values with film thickness the water diffusivity (D) and the oxygen diffusivity (PeO2) values are obtained and are listed in Table 2 also for comparison.

the oxygen diffusivity (PeO2) values are obtained and are listed in Table 2 also for comparison. **Table 2.** Film thickness, water vapor transmission rate (WVTR), water diffusivity (D), oxygen transmission rate (OTR), and oxygen diffusivity (PeO2) values of pure CS/PVOH film as well as CS/PVOH/HNT and CS/PVOH/TO@HNT films.


CS/PVOH/15HNT 0.117 ± 0.012 1.03 ± 0.20 2.75 ± 0.17 44,234 ± 2211 5.97 ± 0.30

CS/PVOH/5TO@HNT 0.140 ± 0.010 1.14 ± 0.13 3.59 ± 0.14 43,345 ± 2167 7.02 ± 0.35 CS/PVOH/10TO@HNT 0.117 ± 0.021 1.02 ± 0.21 2.62 ± 0.17 28,974 ± 1449 3.91 ± 0.20 CS/PVOH/15TO@HNT 0.170 ± 0.017 1.01 ± 0.67 3.64 ± 0.14 30,434 ± 1521 5.64 ± 0.28 For both water and oxygen diffusivity values, in general, could be stated that: (i) the addition of TO@HNT causes a higher increase of water-oxygen barrier than the addition of HNT, (ii) the highest water and oxygen barrier is achieved for films containing 10 wt.%. HNT and 10 wt.%. TO@HNT, and (iii) the film with the optimum water-oxygen barrier is CS/PVOH/10TO@HNT. So, it is concluded that around 10 wt.%. is the optimum content For both water and oxygen diffusivity values, in general, could be stated that: (i) the addition of TO@HNT causes a higher increase of water-oxygen barrier than the addition of HNT, (ii) the highest water and oxygen barrier is achieved for films containing 10 wt.%. HNT and 10 wt.%. TO@HNT, and (iii) the film with the optimum water-oxygen barrier is CS/PVOH/10TO@HNT. So, it is concluded that around 10 wt.%. is the optimum content for both HNT and TO@HNT nanostructures to obtain the highest water/oxygen barrier. This conclusion is consistent with the results of the XRD measurements mentioned above herein. In other words, with 10 % wt. addition of both HNT and TO@HNT in the CS/PVOH matrix the optimum dispersions are achieved to obtain the highest water/oxygen barrier.

for both HNT and TO@HNT nanostructures to obtain the highest water/oxygen barrier.
